Positive type feeding apparatus



March 17, 1964 J. o. FARMER POSITIVE TYPE FEEDING APPARATUS FIG. I 1 e uly 1962 2 ATTORNEY JAMES OTIS FARMER United States Patent 3,124,947 PQSETKVE TYPE FEEDING APPARATUE .lames Utis Farmer, New Castle, Del, assignor to E. l. du Pont tle Nem'ours and Company, Wilmington, Del., a corporation of Delaware 7 Filed July 10, 1962, Ser. No. 208,702 3 Claims. (Cl. 66132) This invention relates to the field of circular knitting machines. More specifically, it relates to an improved mechanism for controlling the feed of yarn or thread to the needles of such machines in a manner which is of special benefit and advantage when handling elastic yarns or threads. The invention is not limited to elastic yarns or threads however. The invention is applicable to circular knitting machines of the rotating cylinder type as well as those of the rotating cam-box type.

In the past a variety of yarn feed mechanisms have been used to control the feed of yarn to the needles of circular knitting machines. These mechanisms have ranged from a simple annular guide mounted on a resilient leaf spring member to devices as disclosed in US. Patents 1,775,033 and 1,420,530, and further to independently powered multiple rotating pin devices currently available commercially. The prior art mechanisms have either failed to perform satisfactorily or possessed certain disadvantages or defects which have made further improvements necessary and desirable. The simple annular guide mounted on a resilient member, for example, cannot control the feed of a yarn to the needles in a positive manner or isolate the yarn in engagement with the needles from variations in tension in the yarn being supplied to the guide. This problem is especially aggravated when elastic yarns are being fed. The other prior art devices mentioned are capable of providing positive feeding of yarn and isolating the needles from tension variations, but these devices are complex and unwieldy, expensive and difficult to install, control, and maintain. Furthermore, the devices disclosed in US. Patents 1,775,033 and 1,420,530 mentioned above must be specially designed for use with any particular machine with which the device is to be used and, in addition, the drive gears engagement with the needles and needle grooves causes nicks, burrs and wear which interferes with proper needle operation.

It is an object of this invention to provide an improved yarn feed mechanism for positively controlling the supply of yarn to the needles of any circular knitting machine, which mechanism is simple and rugged in construction, easy to fabricate, install, operate, and maintain, yet reliable and effective in operation.

It is an object of this invention to provide such a mechanism with a novel combination of structure which operates in an improved manner to maintain elastic yarn feed rates in circular knitting machines uniform to a degree not achieved by the prior art.

It is a further object to provide such an improved mechanism which overcomes the defects and difiiculties encountered in the operation of the prior art mechanisms.

It is yet another object to provide an improved yarn feed mechanism, as discussed above, which requires minimum adjustment in positioning or rate of speed due to wear.

These and other objects are accomplished by a mechanism which comprises, in combination, a yarn engaging means, such as a pulley or pin driven by a rotary means frictionally engaged and rotated by the needles and/or needle grooves of a circular knitting machine as relative motion occurs between the rotary means and the needle grooves and/ or needles, the rotary means comprising a rotatable member mounted for rotation about an axis, said member provided with a plurality of elongated radiice ally extending resiliently flexible elements secured to said member, said elements having terminal portions circumferentially spaced in a given annular path the plane of which is substantially perpendicular to said axis and positioned to frictionally engage the needle grooves and/ or needles, or other suitable structure of a circular knitting machine to impart rotation to said rotatable member and yarn engaging means during relative motion between the said member and the needle grooves and/or needles or other suitable structure.

Other objects and advantages will appear from a consideration of the following specification and claims, taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a partial vertical cross-sectional view through a portion of a typical circular knitting machine of the rotating cylinder type showing a yarn feed mechanism embodying features of this invention,

FIGURE 2 is a partial plan view of the structure and mechanism shown in FIGURE 1,

FIGURE 3 is a cross-sectional view of a modified version of the yarn feed mechanism shown in FIGURE 1. The mechanism is shown in engagement with the cooperating knitting machine structure,

FIGURE 4 is a side elevational view of the mechanism and structure shown in FIGURE 3.

For convenience of disclosure, the yarn feed mechanism of this invention are shown and described in cooperation with usual structure of typical rotating cylinder circular knitting machines such as is disclosed in US. Patent 1,775,033. It will be apparent to those skilled in the art that the mechanism of this invention can equally well be applied to knitting machines of the rotating cam box type.

One simple application of the invention appears in FIGURES l and 2 in which conventional circular knitting machine structure is shown, generally comprising the rotating needle cylinder 28 with needles 68, the cooperating dial plate 36 with its dial needles 67. Elements 20 and 21 are major components of the cam ring assembly which imparts vertical movement to the cylinder needles in a well-known manner when relative rotation occurs between the cam ring assembly and the cylinder.

A yarn feed mechanism supporting frame element 49 with horizontal foot portion 48 is supported on element 2.0 of the cam ring assembly in a suitable manner.

A mounting bracket 12 is secured by machine screw 14 in a cutaway portion of frame element 49 for support of the yarn feed mechanism. A vertical shaft 11 is secured to themounting bnacket 12 by machine screw 13. Rotatably mounted for rotation about shaft 11 is an annular brush unit 10* provided with radially projecting bristle elements of moderate stilfness and having the outer ends thereof in [frictional engagement with structure of the rotating needle cylinder, preferably and most conveniently in direct frictional contact with the outer surfaces of the needles and needle grooves in the rotating needle cylinder so that upon relative motion between the cylinder and the yarn feed mechanism the brush is rotated about shaft 11. Also, mounted on shaft 11 for direct rotation with brush unit 10 is yarn engaging and feeding wheel or pulley 16 connected to unit 10 by suitable means such as drive pin 30. Element 15 shown is a spacer element between the pulley 16 and brush unit 16. The wheel or pulley 16 is secured on the shaft by washer 17 and bolt 18.

An incoming yarn line positioning guide G, mounted on structure, not shown, is positioned as shown to direct incoming yarn from a supply source, not shown, into engagement with the periphery of pulley element 16.

An outgoing yarn line positioning guide is mounted as shown on frame 49 by machine screw 91, at a point between the yarn feed mechanism and the needles to control the position of the yarn line being supplied to the needles.

As shown in FIGURES -1 and 2 an incoming yarn line T, which may comprise one or more filaments or fibers, is led through incoming yarn guide G, in frictional engagement around the periphery of Wheel 16 and through outgoing y-arn guide 90 to the needles.

The operation of the mechanism is believed clear from the drawings and the above description. As cylinder 28 rotates in the direction indicated, its frictional engagement with the ends of bristle elements of brush unit it will rotate brush unit and feed wheel 16' in the direction indicated. Sufiicient frictional engagement is established between yarn line T and the periphery of feed wheel '16 such as by controlling the number of turns of yarn or angular extent of yarn engagement so that there is no slippage of the yarn relative to the periphery of feed wheel 16. Under these conditions the yarn feed mechanism will supply yarn to the knitting machine needles at a rate corresponding to the rate of rotation of the cylinder 28 which is to say, exactly at a controlled rate corresponding to the rate at which it is being used by the machine. In addition, variations in the tension of the incoming yarn line are effectively isolated from the outgoing yarn line being supplied to the needles. The use of the brush or similar means to drive the feed wheel 16 is believed to be responsible for the unusually uniform yarn feed rates and yarn tensions found maintainable in the use of the feed mechanism of this invention. The brush construction, having flexible resilient bristles perrnits a limited peripheral flexing, or accommodation of movement at the area of frictional engagement of the bristles with the driving cylinder structure. This movement can occur without slippage of the ends of the bristle elements and is controlled by increasing resistance proportional to the flexing of the individual bristle elements within limits. This is believed to help smooth out tension variations in the incoming yarn line. The frictional engagement of the brush. unit with movabie knitting machine structure is accomplished without wear or damage to this structure. In addition, the bristles of the brush element can initially be provided with a length somewhat longer than needed for engagement with the rotating machine structure. Due to flexing of the bristle elements this will not affect the effective driving radius of the brush unit and will automatically adjust itself as wear occurs on the outer bristle element ends. It will be obvious that one suitable brush element can satisfactorily engage any needle grooves and/ or needles of any size without adjustment. One type brush found highly satisfactory for use as brush unit 10 is known as a Looper brush manufactured by the Southern Textile Company item Patt. No. 323-nyion bristle. However, it is believed that brush unit 10 could be replaced with a different structure having suitable flexible resilient radially extending elements, such as rubber fingers or other projections of suitable material and form without departing from the spirit of this invention.

The modified version of FIGURES -3 and 4 simply shows a suitable arrangement using a gear reduction arrangement to modify the rotation imparted to the firictionally driven brush unit. A feed mechanism mounting bracket 120 is shown for suitable attachment to the desired knitting machine structure. A shaft element lift is secured to bracket 120 by machine screw 130. A brush unit 100 comprising an annular member M2, to which are secured radially extending bristle elements 1%, is rotatably supported on shaft 110* on bearing 165. A circular gear element 103 is secured to brush unit 10% by machine screw-s 104-. An arm element 173 is rigidly secured to shaft 11ft by lock screw 111, and rotatably supports axle 161 in bearing 162,. At one end of axle 1 61 is rigidly secured a circular gear element 1% which is meshed with gear element 103. At the other end of axle 161 is rigidly secured deed pulley or pin 16% with a yarn engaging groove 165. An incoming yarn feed guide 191 is mounted on bracket 190 which is secured to the end of shaft by machine screw .180. As shown in FIG- URES 3 and 4 the brush unit is in frictional driven engagement with knitting machine structure 689' and 28%? which may be needles and needle grooves respectively. The incoming yarn line T is led through guide 191 and around element a sufficient number of turns to prevent slippage and on to the needles as shown. Relative motion between this machine structure and the feed mechanism in the direction shown by the arrow in FIGURE 4 will cause rotation of the blush unit and controlled feeding of the yarn in substantially the same manner as that described in the structure and mechanism of HG- URES 1 and 2. The brush element can be driven by engagement with either the dial structure or cylinder structure.

It is believed clear that a highly desirable and advantageous new, useful, and improved arrangement for the feeding of yarns to circular knitting machines has been provided.

Although two specific embodiments have been dis closed, it is obvious that many other embodiments and modifications within the spirit of this invention will occur to those skilled in the art and all such are considered to fall within the scope of the following claims.

I claim:

1. An improved yarn feed mechanism for a rotary knitting machine of the type comprising a needle bed structure and a needle actuating cam assembly structure one of said structures being relatively rotatably movable with respect to the other, said improved mechanism comprising, in combination, a yarn engaging feed means for receiving yarn from a supply source and directing said yarn into a knitting machine, a rotary driving means for said feed means and operatively connected therewith, said rotary driving means constructed and arranged to be rotatably supported on the cam assembly structure of a rotary knitting machine and to be positioned in frictional driven engagement with a needle bed structure of such machine so that upon relative rotation between said structure said driving means is rotated to actuate said yarn feed means at a rate proportional to the rate of relative rotation; said driving means comprising a first rotatable member mounted for rotation about an axis, a plurality of elongated resiliently flexible elements secured to said member, said elements having terminal portions circurnferentially spaced in an annular path, the plate of which lies substantially perpendicular to said axis, said terminal portions constructed and arranged for continuous frictional engagement with the needle bed structure of a circular knitting machine to yieldingly impart rotation to said first member during relative rotation between said knitting machine structures, said feed means provided with sufiicient frictional surface for engaging a yarn line to prevent slippage of the yarn line relative to said surface under variations in the tension of the yarn supplied thereto.

2. The improved yarn feed mechanism of claim 1 which further comprises a mounting bracket for supporting said mechanism in operative engagement with the needle bed structure of a circular knitting machine, a shaft element supported on said mounting bracket, said first rotatable member mounted on said shaft, said feed means comprising a second rotatable member having a peripheral surface for frictional engagement with a yarn line, said second rotatable member supported on said bracket and rotated in response to rotation of said first rotatable member.

3. The improved mechanism of claim 2 in which said first rotatable member and said resiliently flexible ele ments of said rotary driving means comprise an annular brush having resiliently flexible bristles for yielding frictional engagement with the needle bed structure of a knitting machine.

References Cited in the file of this patent UNITED STATES PATENTS 6 Walton et a1 Nov. 8, 1927 Wilkinson Sept. 2, 1930 Mayer Aug. 14, 1934 Mayer Oct. 23, 1934 Firsching Jan. 28, 1936 Shortland Nov. 10, 1953 Jackson et a1. Jan. 10, 1961 Rosen May 21, 1963 

1. AN IMPROVED YARN FEED MECHANISM FOR A ROTARY KNITTING MACHINE OF THE TYPE COMPRISING A NEEDLE BED STRUCTURE AND A NEEDLE ACTUATING CAM ASSEMBLY STRUCTURE ONE OF SAID STRUCTURES BEING RELATIVELY ROTATABLY MOVABLE WITH RESPECT TO THE OTHER, SAID IMPROVED MECHANISM COMPRISING, IN COMBINATION, A YARN ENGAGING FEED MEANS FOR RECEIVING YARN FROM A SUPPLY SOURCE AND DIRECTING SAID YARN INTO A KNITTING MACHINE, A ROTARY DRIVING MEANS FOR SAID FEED MEANS AND OPERATIVELY CONNECTED THEREWITH, SAID ROTARY DRIVING MEANS CONSTRUCTED AND ARRANGED TO BE ROTATABLY SUPPORTED ON THE CAM ASSEMBLY STRUCTURE OF A ROTARY KNITTING MACHINE AND TO BE POSITIONED IN FRICTIONAL DRIVEN ENGAGEMENT WITH A NEEDLE BED STRUCTURE OF SUCH MACHINE SO THAT UPON RELATIVE ROTATION BETWEEN SAID STRUCTURE SAID DRIVING MEANS IS ROTATED TO ACTUATE SAID YARN FEED MEANS AT A RATE PROPORTIONAL TO THE RATE OF RELATIVE ROTATION; SAID DRIVING MEANS COMPRISING A FIRST ROTATABLE MEMBER MOUNTED FOR ROTATION ABOUT AN AXIS, A PLURALITY OF ELONGATED RESILIENTLY FLEXIBLE ELEMENTS SECURED TO SAID MEMBER, SAID ELEMENTS HAVING TERMINAL PORTIONS CIRCUMFERENTIALLY SPACED IN AN ANNULAR PATH, THE PLATE OF WHICH LIES SUBSTANTIALLY PERPENDICULAR TO SAID AXIS, SAID TERMINAL PORTIONS CONSTRUCTED AND ARRANGED FOR CONTINUOUS FRICTIONAL ENGAGEMENT WITH THE NEEDLE BED STRUCTURE OF A CIRCULAR KNITTING MACHINE TO YIELDINGLY IMPART ROTATION TO SAID FIRST MEMBER DURING RELATIVE ROTATION BETWEEN SAID KNITTING MACHINE STRUCTURES, SAID FEED MEANS PROVIDED WITH SUFFICIENT FRICTIONAL SURFACE FOR ENGAGING A YARN LINE TO PREVENT SLIPPAGE OF THE YARN LINE RELATIVE TO SAID SURFACE UNDER VARIATIONS IN THE TENSION OF THE YARN SUPPLIED THERETO. 